1. Field of the Invention
This invention relates to racks for storing or holding test tubes and the like, and more particularly to a rack constructed and arranged to hold test tubes or similar vessels in one of two alternating stable operating positions to easily record and indicate to the operator when an operation has been performed upon a particular vessel in a row of such vessels. The invention further relates to test tube racks having optional tube grasping means to hold tubes firmly allowing said rack to serve as a shipping container. The grasping means may also be used to hold said tubes while inverted for draining or incubating in a water bath.
2. Description of the Prior Art
The most pertinent prior art known to the applicant are the U.S. Pat. Nos. Bogley 1,188,146; Hirano 3,923,160; Rem 3,604,566. When an operator is processing a large number of specimens in test tubes in racks of the prior art, no means are provided by the rack or holder to remind him of which tube has been processed last, so that he must rely upon his memory or change in the appearance of the specimen as the result of the last processing step. When the operator is interrupted or distracted during a processing step, he may return to the wrong tube and thereby miss a step or repeat a step on one or more specimens. Some procedures require that each test tube be inverted and the contents drained. Because racks of the prior art make no provision for this procedure, each tube must be individually removed from the rack and drained. Many test tubes are now of light weight material and may contain only small volumes of liquid. When a rack of such tubes is placed in a water bath, the tubes may float out, disrupting the procedure. Racks of the prior art make no provision for preventing this. When a large number of special reagent test tubes such as antibody coated tubes are used they must be removed from their shipping or storage containers and one at a time placed in a test tube rack prior to use.